Add traefic over existing docker-compose configurations


(Not sure if there is many french people here, then i try english :slight_smile: )

I have a starting environment with 3 applications, each one having its docker-compose file.
I think i'll add Traefik to manage the external access and SSL part in a first time (like in the demo on devoxx 2019 :slight_smile: ).

But i'm not sure to understand the global configuration.
In the demo they shows ONE docker-compose file with traefik and the application (or did i miss something ?).
Is it possible to keep my d-c files for applications like i have and "only" add traefik with its d-c file apart ?
(i have gitlab in docker and some local services like a gitlab-runner + wiki, and i hope i could add other softs after my demo)

2 side questions :

  • is there any problems if i stop one applications and restart it later (like for an update, d-c pull && d-c down && d-c up -d) ?
  • for internet exposed applications, do you recommand to change the defaults ports (http/https/ssh for example) to improve security (and with the problem of changing default config) or is it near useless ?

Thx for your answers !